


Not According to Plan

by lord_squiggletits (megatrons_mouth_laser)



Series: Not According to Plan (B-MegOP Smut 'Verse) [1]
Category: The Transformers (IDW Generation One)
Genre: Aftercare, Angry Sex, Bottom Megatron, Bratting, Dirty Talk, Dom/sub Undertones, Flexibility, M/M, Multiple Orgasms, Office Sex, Orgasm Delay/Denial, Plot What Plot/Porn Without Plot, Rough Sex, Sensitivity, Sticky Sexual Interfacing, Sub Megatron, Teasing, optimus prime is tired of being nice and goes apeshit, why don't you get dicked down within an inch of your life and you'll feel better
Language: English
Status: Completed
Published: 2020-10-21
Updated: 2020-10-21
Packaged: 2021-03-09 04:33:40
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,646
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27138043
Author URL: https://archiveofourown.org/users/megatrons_mouth_laser/pseuds/lord_squiggletits
Summary: "So much for being beyond lust," Optimus taunted.
Relationships: Megatron/Optimus Prime
Series: Not According to Plan (B-MegOP Smut 'Verse) [1]
Series URL: https://archiveofourown.org/series/1980904
Comments: 24
Kudos: 228
Collections: Killers_Collections





	Not According to Plan

**Author's Note:**

> Set in some vague post-war peace where Megatron still has his stealth bomber body.
> 
> A short PWP where, as a friend of mine affectionately put it, "It's like Chaos Theory but with porn instead of torture and angst."

It was  _ not _ supposed to happen like this.

Megatron had baited Optimus Prime into their usual sort of office arguments. It had been a delight to speak in circles around him, answer questions with more questions, and generally infuriate him until his fists were clenched and his plating visibly shivered from the effort it took to not leap over the desk and strangle him.

Finally, his composure was sufficiently shattered that he threw his hands in the air and shouted, “Go fuck yourself, Megatron!”

The primary directive of  _ provoke Optimus Prime _ was foremost in Megatron’s processor, making him fire off a response with reflexes as automatic as combat before he consciously thought about it:

“Fuck me yourself, coward.”

For a split second, Optimus’ mask actually moved to snap a response back. Then he froze as Megatron’s exact words registered. He reset his optics and then just stared at him stupidly.

Megatron hadn’t exactly been planning for that response either, but he wasn’t about to show it. He wasn’t done with seeing Optimus’ stoic exterior fall to pieces, either. So instead, he just gave one of his most smug smirks and said, “Are your audio sensors malfunctioning? You heard me.”

He spread his legs in his chair, widening his arrogant sprawl into a brazen invitation.

Optimus stared at him, optics going narrow. “Is this some sort of blackmail attempt?”

“Not at all.” Megatron smiled even wider when Optimus’ gaze actually drifted down between his legs before he snapped it back upwards. “Come now, Prime. You’ve touched me plenty of times in the past four million years. Or do you just not know how to perform?”

“That is...an  _ entirely different context, _ Megatron.” Optimus’ smokestacks puffed steam. His fists tightened at his sides.

“Is it?” Megatron taunted. “You used to know how to make me shut up.”

“Oh, did I?” He growled.

Optimus marched up to him until he stood directly between Megatron’s legs, then knelt at his feet. Megatron had a single moment to wonder which panel he expected him to open before Optimus’ hands shot out and grabbed him under the shoulders, twisting and throwing him on the floor with a grunt of effort.

Megatron laughed, so delighted that he didn’t bother kicking Optimus through the wall like he easily could have in a body this powerful. He wrapped his legs around his waist and pulled him in closer.

There was something in Optimus’ optics, wide and flaring with light, that Megatron couldn’t quite place. It was some mix of fury, determination, and...eagerness, perhaps? He couldn’t admire it for long, however, because the Prime’s mask split open and he fell upon Megatron and kissed him hard.

Where the hell did Optimus get off being such a good kisser? That fragger wouldn't have spent any part of the war with a partner or dallying with his soldiers-- it would've been a liability, an ethical issue, a--

Optimus bit at Megatron's lower lip, and Megatron just stopped thinking about it. His first attempts at kissing back were slightly lacking, but the clash between their lips, over and over again, gave him plenty of opportunities to test what worked. It was all hard teeth and soft lips and probing tongues while they groped at each other blindly, digging fingers into seams and stroking over plating with the same determination they once exchanged blows against each other.

For all that Megatron had been the one to initiate, he was still startled by the slide of Optimus’ hand around his interface array. He had never been touched there by Optimus, much less in such a demanding way. The Prime didn’t seem to favor one panel over the other; he just stroked back and forth between them, holding himself up with the other hand, all while still kissing Megatron hard enough to leave scrape marks on his lips.

They were actually going to interface, Megatron realized, and he wanted it as more than just a game to play with the Prime. He was sorely tempted to open his spike panel and see what Optimus would look like riding it with that furious look on his face, but a different urge prevailed.

The first touch of Optimus' fingers against Megatron's valve sent whispers of pleasant warmth up his sensor net. Those fingers wasted no time in stroking across the rim of his valve from top to bottom, slow like Optimus was savoring the feeling. Megatron shivered. Absolutely no other part of his frame could be described as soft or yielding, but the mesh was exactly that under Optimus' fingers. It felt good.

Megatron released Optimus’ waist with his legs and spread them wider. Then he realized what he was doing and growled.

He had to bite Optimus’ tongue in order to make him retreat. Megatron paused to lick the lingering taste of him off of his lips as he made direct eye contact. “Stalling for time?”

“I’m giving you my full attention,” Optimus growled back. “Isn’t that what you want?”

He pressed his thumb against Megatron’s anterior node, spreading the mesh away from the nub and rubbing the glowing node directly. “Or do you just not know how to handle a valve?”

Megatron could withstand any amount of pain without flinching-- crushing, slicing, melting, electrocution-- but somehow, the pressure of that touch shot through his entire frame with pleasure hot enough to make him gasp before he could stop himself.

His angry snarl was interrupted by Optimus curling a finger inside of his valve, pushing past the first tight ring of callipers and stroking. That was-- that was  _ something, _ alright. His processor pinged a request for “what the hell is this” and was immediately greeted by the cheerful initialization of interface protocols that immediately sucked all his system resources away from tactical processing.

Right. He hadn't done this for millions of years, much less using this specific frame.

Naturally, what followed was that Megatron moaned, loudly, and his entire valve loosened around Optimus’ finger in anticipation of taking a spike whose hypothetical parameters were at the maximum his valve was capable of holding, and suddenly he was lubricating so quickly that he could feel it spurting past Optimus’ finger and tracing a hot path down his aft plating.

_ Damn it. _

“Is there something you  _ want, _ Megatron?” Optimus asked him icily. He waited for Megatron to open his mouth to retort before thrusting another finger inside, making Megatron cut off with a moan again. “Would you like me to  _ stall _ some more, or would you rather I do as you asked and fuck you?”

This was not how things were supposed to go. With Optimus’ fingers buried in his gushing valve, Megatron had no choice but to concede that he hadn’t had a plan to begin with. What else was there to do but to keep moving forward? It was most definitely because he wanted some material to humiliate Prime with later, and because he might as well bask in the satisfaction of infuriating Prime to the point of fragging him, and nothing else at all, that made Megatron reach out and clutch at his hot spike panel suggestively.

Optimus opened for him immediately. Megatron grabbed his spike the instant it finished pressurizing, greedy to feel the shape and girth of it under his fingers. It stood out starkly against his black fingers nicely, too-- all white with gold accents and nodes running down the sides. Megatron pumped it once, gratified to see that the tip was already leaking fluid. Of course he wasn’t the only one affected by this encounter; that was what he had been counting on from the moment he had invited Optimus closer. Megatron could use this to his advantage somehow, if Prime ended up enjoying his valve as much as he was looking forward to Prime’s spike.

Optimus’ fingers slid in and out with ease. Sometimes he paused to spread his valve as wide as it would open around his fingers, making Megatron hiss each time. He was far too dilated and lubricated for it to hurt, but the reality that his valve could even open that wide was certainly new information to him.

Megatron stroked Optimus’ spike again. Well, that was for the best, considering that he was going to need a significant diameter to take this. He gathered the fluid from the spike’s slit at the end of each upstroke and smeared it across the shaft with the next movement downwards. Prime was starting to pant rhythmically with each stroke; Megatron could feel the warm puffs from his cheek vents all the way from where he was laying propped up on one forearm.

He was determined to provoke even more, only Optimus added a third finger and curled them all against a spot inside his valve-- it felt so good and yet not enough at the same time. The inner nodes sparked against Optimus’ fingers, trying to complete a circuit with a spike that wasn’t there. Megatron’s grip on the Prime’s spike faltered.

Optimus pulled his fingers out, rather rudely. Megatron couldn’t decide whether he was more infuriated over the audacity of him pulling out, or the wet, filthy noise his valve had made as soon as Prime moved his fingers. That split second of distraction was enough for Optimus to grab one of Megatron’s ankles and haul his entire leg to prop up against his shoulder, flexing the joint in a way it usually only ever did for his transformation sequence.

“Prime--!” Megatron choked. The position left his legs spread wide. Without Optimus’ fingers or the closeness of his body heat, Megatron was acutely aware of how wet his valve was while the air was brushing against it.

Without further preamble, Optimus thrust inside him, all at once, stretching him wide, shocking his entire valve with the sudden burst of charge. Megatron’s helm fell back to the floor, mouth gaping at the pleasure. It only took a handful of hard, slow thrusts, and then he overloaded.

“Primus,” Optimus hissed above him, and then cursed several more times under his breath. He didn’t stop moving.

_ Yes, yes, yes, yes,  _ Megatron’s interface subsystem sang. Megatron thought deliriously for a moment how grateful he was that this body gave him such flexible joints; there was no way he could've gotten to feel this gloriously full, not just his valve but also his body pushed to their limits. His vocalizer glitched from the force of his second overload as it swept over his frame again in a thought-obliterating wave.

It was definitely not supposed to go like this.

Optimus hitched his leg higher up, then thrust in one last time, seating himself all the way to the hilt and practically splitting Megatron in half. He ground their hips together and moaned as his spike throbbed and spilled inside Megatron’s valve. The hot rush of transfluid was almost enough to make Megatron overload again, but his array had adjusted to the sudden influx of stimulation enough that it kept him barely under the edge.

"Now that I’ve made our positions very clear," Optimus panted, breaking Megatron’s reverie. "Ask me for it."

Megatron had never bowed to pain, and pleasure received the same treatment. "Mmm," he hummed. "No."

The Prime's optics narrowed. He pulled back just enough for Megatron to feel the first ridge at the base of his spike slip free. "Ask me for it."

"No." Megatron squeezed down as soon as Prime tried to move, keeping his spike in place. Both of their engines growled into a higher gear as they fought the stalemate. "You're not about to give this up, Prime."

Optimus bared his teeth. "Watch me."

He pulled away again, and blast him, it worked; Megatron's valve quivered and gave up, too weak from multiple overloads to hold on. Megatron snarled as Optimus pulled out even more, only half of his spike inside now.

"Do you really want to see how far I can go, Megatron? Or will you make this easy for both of us and just give in?"

"Never!" 

"Of course not." Optimus shook his head. When Megatron moved to grab his hips, he fell upon him and pinned his hands down to the floor, leaning all of his body weight until Megatron hissed with pain. Then he pulled away again, and only the head of his spike remained inside.

Charge burned through Megatron's body, and for a moment the crackle of electricity overcame his audio sensors. He felt so empty, he needed more, he  _ wasn't finished yet. _ "You wouldn't," he said, voice calmer than he felt. He made sure to coat his words in as much venom as he could. "Leaving your partner unsatisfied? You don't have the spark for that."

“For you, Megatron? I most certainly do.” And he pulled out the rest of the way.

Megatron dug furrows into the steel floor, gnashing his teeth. With Prime’s spike gone, there was nothing to keep his transfluid from dripping out of Megatron’s valve. He was certain it looked filthy. "I'm going to kill you for that."

"And not have me around to fuck you nice and hard again?"

"I'll remove your spike and keep it as my personal toy."

"I'm sure you would," Optimus said mildly. He reached down and circled Megatron's node with a finger. "Ask me for my spike."

"No," Megatron moaned, low.

"Ah, well if you insist." He lifted his finger and watched with a small smile on his lips as Megatron writhed.

Damn it, with one leg all the way on Prime's shoulder, he couldn't get any leverage to move, much less flip them over and sit down on his spike and ride him until he begged Megatron to stop so he could see how it felt--!

His charge was already simmering slowly downwards. No, no, he would not be denied, he wouldn't. His callipers tried to clamp down on a spike that wasn't there, then dilated, ready and desperate to be filled again. The feeling of cool air brushing his deepest nodes almost hurt, they were so sensitive, and transfluid was still trickling out of his valve and sullying his plating like he was a filthy pleasure drone.

When Megatron focused his optics again, all the motor relays in his body shrieked at once from the rush of electricity. Optimus was staring at Megatron's clenching valve, looking darkly satisfied at the sight. The expression on his face was completely foreign, and yet it looked so right curving his lips and narrowing his optics in pleased smugness.

It also made Megatron’s interface protocols light up with even more eagerness and delight, and this time Megatron could actually feel the clicking of dispensers in his array as a fresh surge of lubricant dribbled out of his clenching valve.

Optimus actually stifled a moan watching that happen, and before Megatron knew it he was being manhandled back on his feet-- he couldn’t seem to get his footing, the motor relays just wouldn’t move from their lax state-- and pushed onto his front. On the surface of his  _ own desk. Bent over and presented _ like his spark was housed in an interface toy instead of the most powerful warframe Cybertron had ever seen.

Megatron screamed as Optimus shoved his spike inside him again, bottoming out in a single rough push. “Bastard!”

Optimus didn’t reply. He just grabbed Megatron by the hips and started fucking him again, pulling his hips back into every thrust so hard that they clanged against Optimus’ own.

The various threats Megatron had queued to spit at him dropped out of conscious processing as yet more system resources were redirected to his interfacing subsystem. He scraped and clutched at the surface of the desk, teeth gritted because he was  _ not _ going to give Optimus the satisfaction of hearing him moan again.

The slagger was obviously enjoying himself. His engine roared, and Megatron could hear the periodic puff of smoke coming from his smokestacks underneath his groans of pleasure. Optimus’ hands kept adjusting their hold on his hips because of how much his grip was shaking.

At that moment, Optimus thrust in deep and ground their hips together. His spike throbbed, filling Megatron with another hot rush of transfluid that had his entire body shivering. Optimus hunched over him, his helm falling against the back of Megatron’s with a click, and moaned low and full-throated.

The resonance of that moan right in his audial shot straight to Megatron’s valve and it was too much, charge and transfluid and Optimus’ thick spike filling him to the brim, and he overloaded with a roar.

"I  _ hate _ you," he growled hoarsely as soon as Optimus stirred on top of him. His vents tickled pleasantly at the back of Megatron’s neck.

The Prime’s engines rumbled in discontent against his back. Then he lifted himself off of Megatron and started pounding again just as hard as before. How much stamina did this pit-spawned mech have?

His valve had no complaints about it. Megatron still couldn’t move the lower half of his body with any finesse, allowing Optimus to easily his pedes against Megatron’s and nudge them until his legs were spread even wider. His harsh pace didn’t waver a fraction.

"You're not so--  _ ahh-- _ high and--!  _ Nnn!-- _ mighty now, are you?" Megatron panted and had to reboot his vocalizer twice before he could keep talking. "You--  _ ghnn-- _ always so virtuous--  _ Oh!-- _ frag like an animal--"

He overloaded again.

When Megatron returned to full awareness a moment later, Optimus had slowed his pace to a languorous slide. Charge teased agonizingly slowly over the contact points in Megatron's valve and he moaned until his vocalizer broke off into static.

"So much for being beyond lust," Optimus taunted. The barbed words were at odds with his gentle pace.

Megatron's engine roared in outrage. "Shut up!"

"No, I don't think I will." Suddenly Optimus' hand was around Megatron's throat, tilting his chin up so his next whisper sounded directly in his audial. "Because the truth is that if you really hated this, you could have easily made me stop at any time. And you didn't, because you like my spike, don't you?" He punctuated the question with a hard thrust.

Megatron choked and didn't respond. How could he, when his pride was being drowned out under the surge of pleasure? Even Optimus’ hand wrapped around his throat felt good. It was increasingly difficult to reason why he shouldn't keep laying here, legs spread and mewling, while Optimus spiked him into overload again, and again, and again. 

Except the Prime  _ pulled out _ because he clearly had a streak of sadism in him after all. “Answer the question.” He tilted Megatron’s head up even further.

Megatron groaned. “Isn’t it obvious?”

“I want to hear you admit it.”

His valve was wet and aching and needy, so Megatron tilted his hips up and muttered, “I like your spike.”

Optimus’ engine revved and he pressed down on Megatron with his entire weight. His spike pressed against Megatron’s valve, parting the folds and sliding back and forth between them. “Ask me to spike you.”

"Spike me," Megatron gasped. He moaned as the tip of Optimus' spike immediately slid inside of him. So close, so close--

"One more word," Prime murmured. "Just one little word and you can have as much as you want."

"Nnnnngh!" Megatron bared his teeth and then let his neck go limp, helm supported entirely by Optimus’ hand. "Please," he hissed.

Optimus pulled away. Megatron nearly screamed at him, except an instant later he took Megatron by the hips and flipped him over, then thrust all the way inside his valve and started a harsh pace. Optimus had one of Megatron’s legs on either side of his helm and held his thighs fast, pulling him in in time with every thrust.

"Say my name."

“Prime...”

“Wrong.”

"Optimus," Megatron breathed, almost inaudible. He was bare, stripped of his armor, and he didn't know whether he wanted to hate the Prime or thank him.

“Do you need it?”

The head of his spike nudged a little deeper, hitting a node cluster that sent lightning across Megatron's circuits.

Megatron bucked upwards into it. “No,” he hissed, defiantly trying to arch his hips back and forth to hit that spot again. He had already asked for it,  _ nicely, _ so why was Optimus still torturing him?

“Oh?” Optimus leaned back, pulling his spike out a few inches. “That’s a shame. I would give you whatever you  _ needed _ , but…”

He reached around and cupped the small of Megatron’s back. The solidness of that broad palm brought an entirely different kind of warmth to Megatron’s plating. It also meant that Optimus had to step closer again, sheathing his spike in deeper, and between that and the support from his hand, Megatron could arch his back, brace his legs harder on Optimus’ shoulders, and rock his hips against his spike.

Megatron’s helm fell to the side and he panted, optics offlining without even thinking about it. Yes, right there,  _ exactly right there-- _

Optimus’ other hand closed on his hip and squeezed, not enough to keep him from moving entirely, but enough to slow the undulation of his hips down to labored rocks. Before Megatron could voice his displeasure, Optimus’ voice was murmuring dark and deep, “Right here?” And he thrust inside, short and sweet.

“No...”

Another thrust, right on the edge of that burning pleasure. “Hm?”

Megatron gasped and clawed at the edges of the desk.

“Do you need it?” Another thrust,  _ there, there, that was it-- _

“No--  _ yes!” _ He had meant to draw it out, defy Optimus and make it known that he was only allowing this by choice, but the sparking in his valve tore the  _ yes _ out of his throat before he could even think to stop it.

“Mmm…” Optimus’ moan sounded both triumphant and gratified. He leaned down until Megatron was nearly bent in half. His voice was uncharacteristically rough as he said, “Now don’t ever hold your voice back.”

He started pounding again, and Megatron didn’t want to hold back. He couldn’t have even if he tried. Every function in his processor dissolved into a haze of pleasure, marked into meaningful periods only by the sharp peaks of overload, the molding together and separation of their mouths, and the sounds of them moaning each other’s names.

  
  
  


Megatron’s circuitry felt like it had been scorched clean. Every part of his frame tingled in a pleasantly exhausted way that he hadn’t experienced in this frame before; nothing else had been able to drive him to his limits. He didn’t have to think about anything, just lay relaxed and enjoy it.

He sensed a change in his environment; a pair of arms slowly rested him on a hard, cool surface, and Megatron realized that Optimus had just been  _ carrying _ him. He onlined his optics just in time to see Optimus turning the dials on the wall, sending a stream of solvent pattering onto Megatron’s plating. Wash racks, then.

Optimus turned and noticed that he was awake. His mask was still down. In a soft voice he asked, “How do you feel?”

Megatron frowned up at the ceiling. “Fine,” he answered at last.  _ Fine _ didn’t even scratch the surface of the complete relaxation and satiation in every inch of his frame. Megatron couldn’t even move his legs, actually; the signals just couldn’t get past his interface array, which was still taking up as much power as it could without being actively in use. But the Prime didn’t need to know how much power he had. Not yet, anyways.

“I’m sorry.”

Megatron blinked. “What the hell?”

Optimus kneeled on the floor next to him. His shoulders slumped, he covered his face, and he said meekly, “I didn’t ask you properly for permission, much less treat you how anyone should be treated during interfacing. I let my anger control me, and I treated you inexcusably.”

Megatron stared some more. Then: “Are you malfunctioning?”

Some of that absurdly apologetic expression faded from Optimus’ face “I am functioning just fine, and I am very serious about this,” he said slowly. “But you are the one I am far more concerned for--”

He stopped at the sound of Megatron clanking his helm back loudly against the shower floor. “I obviously wanted it, fool.” The words came out with significantly less anger than he normally would’ve given them. The pleasant tingling all over his body was too strong.

“Obviously? Half the time you were screaming insults at me!”

Megatron still couldn’t move his legs, so he settled with reclining back on one elbow. “What, do you think I would’ve let you bend me over my own desk and fuck me senseless without making you work to get it out of me?”

Optimus rumbled. “That does sound like something you would do, but the point is that there are  _ principles _ about interfacing with someone--”

“Ugh, will you stop? Get down here.” Megatron waved imperiously and stared Optimus down until he sighed and sank to his knees next to him. Then he grabbed his shoulder guard, pulled him down, and kissed him, using his full strength to keep their faces together until Optimus kissed him back with equal enthusiasm.

“I wanted it,” Megatron panted after they separated. “I wanted it, and I enjoyed it, and I would do it again without any regrets.”

Optimus looked deeply into Megatron’s optics, then sighed, seemingly accepting his words. “You should also know that I went through some of your cabinets to find cleaning supplies for our little mess.”

“I would have been very displeased with you if you had ruined my desk without cleaning it up.” Megatron grinned up at him.

“And while we are on the subject of cleaning…” Optimus made an awkward gesture at the lower half of Megatron’s body. “Would you rather handle this by yourself, or…?”

Embarrassment looked good on the Prime, so Megatron leered and said, “You should clean up  _ all _ of your messes, yes.”

Optimus rolled his optics. “You’re the one who started it, but fine.”

For all his initial hesitance, Optimus’ touch with the washcloth was surprisingly gentle as he dabbed carefully at Megatron’s valve and inner thighs. He even took the time to thoroughly clean between the seams of his plating and in his joints, leaving no drop of fluid left uncleaned. Very nice.

Unfortunately, Optimus ruined the mood again. “Is there anything else you need me to do?” he murmured. “I want to make up for...what I did.”

Was Prime always this dense? Oh yes, of course; it was that blasted sense of honor as always. "I am perfectly capable of making it clear when I do not want something," Megatron said sharply. If Prime was about to start coddling him...

"That's not what I meant." Optimus sighed and rested his hands on his thighs. "I just want to be sure you never feel like I'm treating you disrespectfully, because I  _ do  _ respect you, Megatron. I don’t want to presume what it is you do or do not want."

"Hmm." Still as sentimental as ever, but Megatron could get used to hearing that kind of confession from Optimus. The mood was getting far too morose, however, so Megatron grinned and purred, "Why don't you respectfully come down here and kiss me, then."

His sanctimonious speech interrupted, Optimus shook his head and threw up his hands. “You are a  _ menace.” _ He leaned down and kissed him anyways.

“Obviously.” Megatron smiled into the kiss and nibbled at Optimus’ lower lip until he sighed and pressed closer.

The sweet afterglow coursing through his circuitry, the pleasure of seeing Optimus’ dominant side being let loose… Things hadn’t gone according to plan, but Megatron had still won something, in a sense.

And he would win even more once he returned the favor to Optimus.

**Author's Note:**

> Next entry in the series: Megatron tries to woo Optimus into his berth. Plans are made, shenanigans ensue, and feelings are caught.


End file.
